Mobile devices, mobile systems and operating methods thereof

ABSTRACT

A first mobile device including a connection terminal configured to electrically connect to a second mobile device, a variable impedance device connected to the connection terminal, the variable impedance device configured to vary an impedance, processing circuitry configured to determine a power line communication (PLC) mode between the first mobile device and the second mobile device to be one of a low-speed PLC mode or a high-speed PLC mode, and control the impedance of the variable impedance device according to the determined PLC mode, and a PLC modem configured to receive power from the second mobile device or communicate data with the second mobile device based on the determined PLC mode.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of Korean Patent Application No.10-2019-0175501, filed on Dec. 26, 2019, in the Korean IntellectualProperty Office, the disclosure of which is incorporated herein in itsentirety by reference.

BACKGROUND

The inventive concepts relate to a mobile device, and more particularly,to a mobile device and an operating method thereof.

Wireless earphones are devices that receive audio signals via a wirelessconnection and output sound. Such wireless earphones include acommunication module, e.g., a Bluetooth module, for near fieldcommunication and a battery to supply driving power to the communicationmodule. As dedicated chargers for charging a battery of wirelessearphones, charging cases that house the wireless earphones and chargethe battery of the wireless earphones are widely used. Moreover, thereis an increasing demand for data exchange between wireless earphones anda charging case.

SUMMARY

According to an aspect of the inventive concepts, there is provided afirst mobile device including a connection terminal configured toelectrically connect to a second mobile device, a variable impedancedevice connected to the connection terminal, the variable impedancedevice configured to vary an impedance, processing circuitry configuredto determine a power line communication (PLC) mode between the firstmobile device and the second mobile device to be one of a low-speed PLCmode or a high-speed PLC mode, and control the impedance of the variableimpedance device according to the determined PLC mode, and a PLC modemconfigured to receive power from the second mobile device or communicatedata with the second mobile device based on the determined PLC mode.

According to an aspect of the inventive concepts, there is provided asecond mobile device including a connection terminal configured toelectrically connect to a first mobile device, a variable impedancedevice connected to the connection terminal, the variable impedancedevice configured to vary an impedance, processing circuitry configuredto determine a power line communication (PLC) mode to be one of alow-speed PLC mode or a high-speed PLC mode, control the impedance ofthe variable impedance device according to the determined PLC mode,receive an input voltage from an external source, and generate aconverted voltage from the input voltage, and a PLC modem configured totransmit power to the first mobile device or communicate data with thefirst mobile device based on the determined PLC mode, the power beingbased on the converted voltage.

According to an aspect of the inventive concepts, there is provided amobile system including a first mobile device and a second mobiledevice, the first mobile device and the second mobile device beingconfigured to transfer power and data with each other using power linecommunication (PLC), wherein the first mobile device includes a firstconnection terminal configured to electrically connect to the secondmobile device, a first variable impedance device connected to the firstconnection terminal, and first processing circuitry configured todetermine a first PLC mode between the first mobile device and thesecond mobile device to be one of a low-speed PLC mode or a high-speedPLC mode, and control an impedance of the first variable impedancedevice according to the determined first PLC mode, and the second mobiledevice includes a second connection terminal configured to electricallyconnect to the first mobile device, a second variable impedance deviceconnected to the second connection terminal, and second processingcircuitry configured to determine a second PLC mode between the firstmobile device and the second mobile device to be the one of thelow-speed PLC mode or the high-speed PLC mode, and control an impedanceof the second variable impedance device according to the determinedsecond PLC mode.

According to an aspect of the inventive concepts, there is provided anoperating method of a first mobile device. The operating method includesreceiving a host request from a second mobile device through aconnection terminal in a low-speed power line communication (PLC) mode,changing a PLC mode between the first mobile device and the secondmobile device from the low-speed PLC mode to a high-speed PLC modeincluding increasing an impedance of a signal line in response to thehost request, the signal line being connected to the connectionterminal, receiving data from the second mobile device in the high-speedPLC mode, and changing the PLC mode from the high-speed PLC mode to thelow-speed PLC mode including decreasing the impedance of the signal linebased on completion of the receiving the data.

According to an aspect of the inventive concepts, there is provided anoperating method of a second mobile device. The operating methodincludes transmitting a host request to a first mobile device through aconnection terminal in a low-speed power line communication (PLC) mode,receiving a client response from the first mobile device as a responseto the host request, changing a PLC mode between the first mobile deviceand the second mobile device from the low-speed PLC mode to a high-speedPLC mode including increasing an impedance of a signal line based on theclient response, the signal line being connected to the connectionterminal, transmitting data to the first mobile device in the high-speedPLC mode, and changing the PLC mode from the high-speed PLC mode to thelow-speed PLC mode including decreasing the impedance of the signal linebased on completion of the transmitting the data.

BRIEF DESCRIPTION OF THE DRAWINGS

Some example embodiments of the inventive concepts will be more clearlyunderstood from the following detailed description taken in conjunctionwith the accompanying drawings in which:

FIG. 1 illustrates a mobile system according to some exampleembodiments;

FIG. 2 illustrates a power line communication (PLC) mode between a firstmobile device and a second mobile device over time, according to someexample embodiments;

FIG. 3 illustrates a mobile system according to some exampleembodiments;

FIG. 4 is a flowchart of the operations between a first mobile deviceand a second mobile device, according to some example embodiments;

FIG. 5 illustrates a mobile system according to some exampleembodiments;

FIG. 6 is a timing diagram of an example of PLC data exchange between afirst mobile device and a second mobile device, according to someexample embodiments;

FIG. 7 is a timing diagram of another example of PLC data exchangebetween a first mobile device and a second mobile device, according tosome example embodiments;

FIG. 8 illustrates a mobile system according to some exampleembodiments;

FIG. 9 illustrates a mobile system according to some exampleembodiments;

FIG. 10 is a timing diagram of an example of PLC data exchange between afirst mobile device and a second mobile device, according to someexample embodiments;

FIG. 11 illustrates a mobile system according to some exampleembodiments; and

FIG. 12 is a flowchart of the operations among a first mobile device, asecond mobile device, and a main device, according to some exampleembodiments.

DETAILED DESCRIPTION

Hereinafter, some example embodiments will be described in detail withreference to the accompanying drawings.

FIG. 1 illustrates a mobile system 10 according to some exampleembodiments.

Referring to FIG. 1, the mobile system 10 may include a first mobiledevice (MD1) 100 and a second mobile device (MD2) 200. The first mobiledevice 100 may exchange power and data with the second mobile device 200through power line communication (PLC). The first mobile device 100 mayinclude a first connection terminal T1, which is configured to beelectrically connected to the second mobile device 200, and may receivepower from the second mobile device 200 or exchange data with the secondmobile device 200 through the first connection terminal T1. Similarly,the second mobile device 200 may include a second connection terminalT2, which is configured to be electrically connected to the first mobiledevice 100, and may supply power to the first mobile device 100 orexchange data with the first mobile device 100 through the secondconnection terminal T2.

PLC is communication technology for transferring power and data througha power line 300. For example, the power line 300 may be realized viaelectrical contact between the first connection terminal T1 and thesecond connection terminal T2 so that the first and second mobiledevices 100 and 200 may exchange power and data with each other. Inconventional mobile devices, a pin separate from the electrical contactis included for use in data exchange. As a result, the size of theconventional mobile devices is increased to accommodate this separatepin.

However, according to some example embodiments, the first mobile device100 does not include a separate connection terminal or pin for dataexchange with the second mobile device 200 and may exchange data withthe second mobile device 200 through the first connection terminal T1that receives power. Similarly, the second mobile device 200 does notinclude a separate connection terminal or pin for data exchange with thefirst mobile device 100 and may exchange data with the first mobiledevice 100 through the second connection terminal T2 that transmitspower. Accordingly, some example embodiments improve over thedeficiencies of the conventional mobile devices enable reduction of thesize of each of the first mobile device 100 and the second mobile device200 by omission of the separate pin. Such a reduction in size isparticularly advantageous in mobile devices for which a small size isoften desirable.

The first mobile device 100 may further include a variable impedanceunit 110 (also referred to herein as a variable impedance device), acontroller 120, a PLC modem 130, and/or a first battery (BAT1) 140. Thevariable impedance unit 110 may be electrically connected to the firstconnection terminal T1, may include an impedance element such as aresistor or a capacitor, and may have variable impedance under thecontrol of the controller 120. For example, the variable impedance unit110 may include at least one variable resistor. In another example, thevariable impedance unit 110 may include at least one resistor and atleast one switch.

The controller 120 may determine a PLC mode between the first mobiledevice 100 and the second mobile device 200 to be one of a plurality ofPLC modes including a low-speed PLC mode and a high-speed PLC mode. Forexample, the low-speed PLC mode may correspond to a power communicationmode that transmits power through PLC. For example, the high-speed PLCmode may correspond to a data communication mode that transmits andreceives data through PLC. According to some example embodiments, thePLC modes may further include at least one selected from a PLC modehaving a communication speed between the communication speed of thelow-speed PLC mode and the communication speed of the high-speed PLCmode, a PLC mode having a lower communication speed than the low-speedPLC mode, and/or a PLC mode having a higher communication speed than thehigh-speed PLC mode

The controller 120 may control the impedance of the variable impedanceunit 110 according to the determined PLC mode. For example, thecontroller 120 may control the variable impedance unit 110 to have afirst impedance in the low-speed PLC mode and to have a secondimpedance, which is higher than the first impedance, in the high-speedPLC mode. The controller 120 may also control the PLC modem 130according to the determined PLC mode. Furthermore, the controller 120may control the first battery 140 to be charged based on the powerreceived from the second mobile device 200. For example, the controller120 may include a micro control unit (MCU). However, some exampleembodiments are not limited thereto, and the controller 120 may includea processor or a central processing unit (CPU).

The PLC modem 130 may receive power from the second mobile device 200and/or exchange data with the second mobile device 200, based on thedetermined PLC mode. In detail, the PLC modem 130 may modulate a signal(e.g., voltage and/or current) to be output through the first connectionterminal T1 and/or demodulate a signal received from the firstconnection terminal T1. For example, the PLC modem 130 may include acurrent source, a current modulator, and/or a voltage demodulator. Thiswill be described with reference to FIG. 5 below.

The second mobile device 200 may further include a variable impedanceunit 210, a controller 220, a PLC modem 230, and/or a second battery(BAT2) 240. In some example embodiments, the second mobile device 200may further include an input voltage terminal Tin, which may receive aninput voltage Vin from the outside of the second mobile device 200. Forexample, the input voltage terminal Tin may receive the input voltageVin from a household power supply, e.g., alternating current (AC) about110 Volts to 220 Volts, or another power supply unit (e.g., a computeror an auxiliary battery). In some example embodiments, the second mobiledevice 200 may wirelessly receive the input voltage Vin from the outsidethereof.

The variable impedance unit 210 may be electrically connected to thesecond connection terminal T2, may include an impedance element such asa resistor or a capacitor, and may have variable impedance under thecontrol of the controller 220. The variable impedance unit 210 may bethe same as or substantially similar to the variable impedance unit 110,and the above descriptions of the variable impedance unit 110 may alsobe applied to the variable impedance unit 210.

The controller 220 may determine a PLC mode between the first mobiledevice 100 and the second mobile device 200 to be one of a plurality ofPLC modes including a low-speed PLC mode and a high-speed PLC mode. Thecontroller 220 may control the impedance of the variable impedance unit210 according to the determined PLC mode. For example, the controller220 may control the variable impedance unit 210 to have first impedancein the low-speed PLC mode and to have second impedance, which is higherthan the first impedance, in the high-speed PLC mode. The controller 220may also control the PLC modem 230 according to the determined PLC mode.Furthermore, the controller 220 may control the second battery 240 to becharged based on the input voltage Vin. The controller 220 may be thesame as or substantially similar to the controller 120, and the abovedescriptions of the controller 120 may also be applied to the controller220.

The PLC modem 230 may supply power to the first mobile device 100 and/orexchange data with the first mobile device 100, based on the determinedPLC mode. In detail, the PLC modem 230 may modulate a signal (e.g.,voltage and/or current) to be output through the second connectionterminal T2 and/or demodulate a signal received from the secondconnection terminal T2. For example, the PLC modem 230 may include alow-speed PLC modem operating in the low-speed PLC mode and a high-speedPLC modem operating in the high-speed PLC mode. This will be describedwith reference to FIG. 3 below.

In some example embodiments, the first mobile device 100 may include awireless earbud or a wireless earphone, and the second mobile device 200may include a wireless earbud charger or a wireless earphone charger.Through PLC via the electrical contact between the first connectionterminal T1 and the second connection terminal T2, the second mobiledevice 200 may charge the first mobile device 100, and the first mobiledevice 100 and the second mobile device 200 may exchange data with eachother. According to some example embodiments, the first mobile device100 and the second mobile device 200 may exchange data through the firstand second connection terminals T1 and T2 that transmit power, withoutincluding separate terminals for data exchange.

In general, a mobile device includes a battery and a power managementintegrated circuit (PMIC) managing the battery. To implement PLC, thePMIC in conventional mobile devices may change a voltage level of apower line through current and/or voltage control. At this time, becauseof current and/or voltage control speed limitations of the PMIC, ittakes a significant amount of time for conventional mobile devices toexchange a large amount of data.

However, according to some example embodiments, the first and secondmobile devices 100 and 200 may determine the PLC mode to be thehigh-speed PLC mode for data exchange, and may increase the impedance ofthe variable impedance units 110 and 210 connected to the power line 300in the high-speed PLC mode. As described above, according to someexample embodiments, the first and second mobile devices 100 and 200 mayefficiently support the low-speed PLC mode and the high-speed PLC modeby changing the impedance of the variable impedance units 110 and 210according to a communication speed through the power line 300.Accordingly, the first and second mobile devices 100 and 200 may improveover the deficiencies of the conventional mobile devices to exchangemore data in less time (e.g., at a higher data rate) than theconventional mobile devices.

FIG. 2 illustrates a PLC mode between the first mobile device 100 andthe second mobile device 200 over time, according to some exampleembodiments.

Referring to FIG. 2, in a power communication phase or a power transferphase 21, the second mobile device 200 may transmit power to the firstmobile device 100. At this time, the PLC mode between the first andsecond mobile devices 100 and 200 may be determined to be the low-speedPLC mode. In a host/client define phase 22, a host transmitting data anda client receiving the data may be determined between the first andsecond mobile devices 100 and 200. At this time, the PLC mode betweenthe first and second mobile devices 100 and 200 may be still determinedto be the low-speed PLC mode. For example, the second mobile device 200may be determined to be the host and the first mobile device 100 may bedetermined to be the client.

In a data communication phase or a data transfer phase 23, the host maytransmit data to the client. At this time, the PLC mode between thefirst and second mobile devices 100 and 200 may be determined to be thehigh-speed PLC mode. For example, the second mobile device 200 maytransmit data to the first mobile device 100. In the data transfer phase23, the main function of the power line 300 may be changed from powertransfer to data transfer. In some example embodiments, only data may betransmitted through the power line 300 in the data transfer phase 23.However, some example embodiments are not limited thereto. Power anddata may be transmitted through the power line 300 in the data transferphase 23.

When data transfer is completed, a power transfer phase 24 begins anew,and the PLC mode between the first and second mobile devices 100 and 200may be determined to be the low-speed PLC mode. The main function of thepower line 300 may be changed from data transfer to power transfer inthe power transfer phase 24. In some example embodiments, only power maybe transmitted through the power line 300 in the power transfer phase24. However, some example embodiments are not limited thereto. Data andpower may be transmitted through the power line 300 in the powertransfer phase 24.

FIG. 3 illustrates a mobile system 10 a according to some exampleembodiments.

Referring to FIG. 3, the mobile system 10 a may include a first mobiledevice 100 a and a second mobile device 200 a. The first and secondmobile devices 100 a and 200 a may correspond to examples of the firstand second mobile devices 100 and 200 in FIG. 1. The descriptions givenabove with reference to FIGS. 1 and 2 may also be applied to FIG. 3.

The first mobile device 100 a may include the first connection terminalT1, a variable impedance unit 110 a, the controller 120, the PLC modem130, a first battery 140 a, and/or a charge circuit or a charger 150.For example, the variable impedance unit 110 a, the controller 120, thePLC modem 130, the first battery 140 a, and/or the charger 150 may bemounted on a printed circuit board (PCB). The controller 120 may controlan impedance Z1 of the variable impedance unit 110 a according to thePLC mode. In detail, the controller 120 may determine the impedance Z1to be the first impedance in the low-speed PLC mode and to be the secondimpedance, which is higher than the first impedance, in the high-speedPLC mode. The controller 120 may also control the PLC modem 130according to the PLC mode.

The charger 150 may be a linear charger and may be implemented as acharging IC. The controller 120 may control the operation of the charger150 based on the PLC mode. For example, in the power transfer phase 21(in FIG. 2), the PLC mode may be the low-speed PLC mode, and thecontroller 120 may activate the charger 150 and thus charge the firstbattery 140 a with a battery voltage VBAT1 using power received throughthe power line 300. For example, in the data transfer phase 23 (in FIG.2), the PLC mode may be the high-speed PLC mode, and the controller 120may deactivate the charger 150 and the first mobile device 100 a mayoperate using the battery voltage VBAT1 of the first battery 140 a.

The second mobile device 200 a may include the second connectionterminal T2, a variable impedance unit 210 a, the controller 220, a PLCmodem 230 a, a second battery 240 a, and/or a converter 250. Forexample, the variable impedance unit 210 a, the controller 220, the PLCmodem 230 a, the second battery 240 a, and/or the converter 250 may bemounted on a PCB. The controller 220 may control an impedance Z2 of thevariable impedance unit 210 a according to the PLC mode. In detail, thecontroller 220 may determine the impedance Z2 to be the first impedancein the low-speed PLC mode and to be the second impedance, which ishigher than the first impedance, in the high-speed PLC mode. The PLCmodem 230 a may include a low-speed PLC modem 231 and/or a high-speedPLC modem 232, which may selectively operate. The controller 220 mayactivate the low-speed PLC modem 231 in the low-speed PLC mode andactivate the high-speed PLC modem 232 in the high-speed PLC mode.

In some example embodiments, the converter 250 may include a switchingregulator, which generates a converted voltage Vc from the input voltageVin and/or a battery voltage VBAT2 of the second battery 240 a, whereinthe input voltage Vin is received from the outside of the second mobiledevice 200 a through the input voltage terminal Tin. The converter 250may be a direct current (DC)-DC converter. For example, the converter250 may be a step-up converter (e.g., a boost converter) that convertsthe input voltage Vin and/or the battery voltage VBAT2, which isrelatively low, into the converted voltage Vc, which is relatively high,and/or a step-down converter (e.g., a buck converter) that converts theinput voltage Vin and/or the battery voltage VBAT2, which is relativelyhigh, into the converted voltage Vc, which is relatively low. Theconverter 250 may also charge the second battery 240 a with the batteryvoltage VBAT2 based on the input voltage Vin, which is received from theoutside of the second mobile device 200 a.

In some example embodiments, each of the first and second batteries 140a and 240 a may include at least one battery cell. For example, thefirst battery 140 a and/or the second battery 240 a may be a multi-cellbattery including a plurality of battery cells connected in series toeach other. In some example embodiments, each of the first and secondbatteries 140 a and 240 a may include at least one battery pack. Forexample, the first battery 140 a and/or the second battery 240 a may beimplemented by a battery device including a plurality of battery packsconnected in series to each other.

FIG. 4 is a flowchart of the operations between the first mobile device100 a and the second mobile device 200 a, according to some exampleembodiments.

Referring to FIG. 4, the second mobile device 200 a may generate a hostrequest (e.g., REQ in FIG. 6) in operation S110. The second mobiledevice 200 a may transmit the host request to the first mobile device100 a in operation S120. The first mobile device 100 a may generate aclient response (e.g., RES in FIG. 6) in response to the host request inoperation S130. The first mobile device 100 a may transmit the clientresponse to the second mobile device 200 a in operation S140. Forexample, operations S110 through S140 may correspond to the host/clientdefine phase 22 in FIG. 2, and both of the first and second mobiledevices 100 a and 200 a may operate in the low-speed PLC mode. At thistime, the impedances Z1 and Z2 of the variable impedance units 110 a and210 a respectively included in the first and second mobile devices 100 aand 200 a may be relatively low.

The second mobile device 200 a may determine the PLC mode to be thehigh-speed PLC mode in operation S150 (e.g., based on the clientresponse). Accordingly, the impedance Z2 of the variable impedance unit210 a of the second mobile device 200 a may increase, the high-speed PLCmodem 232 may be activated, and the low-speed PLC modem 231 may bedeactivated. The first mobile device 100 a may determine the PLC mode tobe the high-speed PLC mode in operation S155 (e.g., based on sending theclient response in operation S140). Accordingly, the impedance Z1 of thevariable impedance unit 110 a of the first mobile device 100 a mayincrease. Operations S150 and S155 may be performed substantiallysimultaneously or contemporaneously.

The second mobile device 200 a may transmit data to the first mobiledevice 100 a in operation S160. For example, the data may correspond tofirmware, and the second mobile device 200 a may transmit the firmware,which is downloaded from a host, to the first mobile device 100 a. Whena failure occurs in an Integrated Circuit (IC) (e.g., an IC of the firstmobile device 100 a) after the first mobile device 100 a is launched,the first mobile device 100 a may repair the failure in the IC using thefirmware received from the second mobile device 200 a. For example,operations S150 through S160 may correspond to the data transfer phase23 in FIG. 2. According to some example embodiments, operations S110through S140 may correspond to a detection of a failure of an IC of thefirst mobile device 100 a, detection of a firmware update that should beprovided to the first mobile device 100 a, and/or a request to transferthe firmware configured to repair the failure and/or facilitate thefirmware update. According to some example embodiments, the first mobiledevice 100 a may store, install and/or execute the received firmwarefollowing operation S160. According to some example embodiments, thefirst mobile device 100 a may repair the failure of the IC using thereceived firmware following operation S160.

The second mobile device 200 a may determine the PLC mode to be thelow-speed PLC mode in operation S170 (e.g., based on completion of thetransmission of the data in operation S160). Accordingly, the impedanceZ2 of the variable impedance unit 210 a of the second mobile device 200a may decrease, the low-speed PLC modem 231 may be activated, and thehigh-speed PLC modem 232 may be deactivated. The first mobile device 100a may determine the PLC mode to be the low-speed PLC mode in operationS175 (e.g., based on completion of the transmission of the data inoperation S160). Accordingly, the impedance Z1 of the variable impedanceunit 110 a of the first mobile device 100 a may decrease. OperationsS170 and S175 may be performed substantially simultaneously orcontemporaneously. The second mobile device 200 a may transmit power tothe first mobile device 100 a in operation S180. For example, operationsS170 through S180 may correspond to the power transfer phase 24 in FIG.2.

FIG. 5 illustrates a mobile system 10 b according to some exampleembodiments.

Referring to FIG. 5, the mobile system 10 b may include a first mobiledevice 100 b and a second mobile device 200 b. The first and secondmobile devices 100 b and 200 b may correspond to examples of the firstand second mobile devices 100 a and 200 a in FIG. 3. Therefore, thedescriptions given above with reference to FIGS. 3 and 4 may also beapplied to FIG. 5. When the first mobile device 100 b is connected tothe second mobile device 200 b by the electrical contact between thefirst and second connection terminals T1 and T2, a line current I_(PL)may flow through the power line 300, and the respective voltages of thefirst and second connection terminals T1 and T2 may be the same as orsimilar to each other at a line voltage V_(PL).

The first mobile device 100 b may include the first connection terminalT1, the variable impedance unit 110 a, the controller 120, a PLC modem130 a, the first battery 140 a, and/or the charger 150. The controller120 may generate a control signal for controlling the PLC modem 130 aaccording to the PLC mode. The PLC modem 130 a may include a currentmodulator (MOD) 131, a voltage demodulator (DEMOD) 132, and/or a currentsource 133. The current MOD 131 may receive the control signal from thecontroller 120 and generate a current modulation signal according to thecontrol signal. The current source 133 may generate a current pulseaccording to the current modulation signal and provide the current pulseto the first connection terminal T1. The voltage DEMOD 132 may generatevoltage demodulation signal according to the line voltage V_(PL) of thefirst connection terminal T1 and provide the voltage demodulation signalto the controller 120.

The second mobile device 200 b may include the second connectionterminal T2, the variable impedance unit 210 a, the controller 220, avoltage MOD 231 a, a current DEMOD 231 b, a current MOD 232 a, a voltageDEMOD 232 b, a current source 233, the second battery 240 a, and/or theconverter 250. According to the PLC mode, the controller 220 maygenerate control signals for controlling the voltage MOD 231 a, thecurrent DEMOD 231 b, the current MOD 232 a, the voltage DEMOD 232 b,and/or the current source 233. At this time, the voltage MOD 231 a andthe current DEMOD 231 b may be activated in the low-speed PLC mode andmay form the low-speed PLC modem 231 in FIG. 3. The current MOD 232 a,the voltage DEMOD 232 b, and the current source 233 may be activated inthe high-speed PLC mode and may form the high-speed PLC modem 232 inFIG. 3.

In the low-speed PLC mode, the controller 220 may activate the voltageMOD 231 a and the current DEMOD 231 b, and deactivate the current MOD232 a, the voltage DEMOD 232 b, and the current source 233. In thelow-speed PLC mode, the voltage MOD 231 a may receive a control signalfrom the controller 220 and generate a voltage modulation signalaccording to the control signal. The voltage MOD 231 a may transmit thevoltage modulation signal to the first mobile device 100 b through thevariable impedance unit 210 a and the second connection terminal T2. Thevoltage MOD 231 a may include a linear regulator, e.g., a low drop-out(LDO) regulator. The current DEMOD 231 b may generate a currentdemodulation signal according to the line current I_(PL) receivedthrough the second connection terminal T2 and provide the currentdemodulation signal to the controller 220.

In the high-speed PLC mode, the controller 220 may deactivate thevoltage MOD 231 a and the current DEMOD 231 b and activate the currentMOD 232 a, the voltage DEMOD 232 b, and the current source 233. In thehigh-speed PLC mode, the current MOD 232 a may receive a control signalfrom the controller 220 and generate a current modulation signalaccording to the control signal. The current source 233 may generate acurrent pulse according to the current modulation signal and provide thecurrent pulse to the second connection terminal T2. The voltage DEMOD232 b may generate a voltage demodulation signal according to the linevoltage V_(PL) of the second connection terminal T2 and provide thevoltage demodulation signal to the controller 220.

FIG. 6 is a timing diagram of an example of PLC data exchange betweenthe first mobile device MD1 and the second mobile device MD2, accordingto some example embodiments.

Referring to FIG. 6, a first graph 610 represents a line voltage overtime and may correspond to, for example, the line voltage V_(PL) of thefirst or second connection terminal T1 or T2 connected to the power line300 in FIG. 5. A second graph 620 represents a line current over timeand may correspond to, for example, the line current I_(PL) flowing inthe power line 300 in FIG. 5. For example, the first and second mobiledevices MD1 and MD2 may respectively correspond to the first and secondmobile devices 100 b and 200 b in FIG. 5. Hereinafter, descriptions willbe made with reference to FIGS. 5 and 6.

A time period from a time point t1 to a time point t2 may correspond toa host/client define phase 61. At this time, the first and second mobiledevices 100 b and 200 b may operate in the low-speed PLC mode. Theimpedances Z1 and Z2 of the variable impedance units 110 a and 210 arespectively included in the first and second mobile devices 100 b and200 b may be relatively low. In some example embodiments, the impedanceZ1 of the variable impedance unit 110 a may be equal or similar to theimpedance Z2 of the variable impedance unit 210 a in the host/clientdefine phase 61. However, some example embodiments are not limitedthereto. In some example embodiments, the impedance Z1 of the variableimpedance unit 110 a may be different from the impedance Z2 of thevariable impedance unit 210 a in the host/client define phase 61.

In the host/client define phase 61, the second mobile device 200 b maytransmit a host request REQ to the first mobile device 100 b, and thefirst mobile device 100 b may transmit a client response RES to thesecond mobile device 200 b in response to the host request REQ.According to some example embodiments, the host request REQ and theclient response RES may be exchanged at least two times in thehost/client define phase 61.

In the host/client define phase 61, the converter 250 and the voltageMOD 231 a of the second mobile device 200 b may be activated, and thevoltage MOD 231 a may generate a voltage modulation signal from theconverted voltage Vc, which is received from the converter 250,according to a control signal received from the controller 220. However,some example embodiments are not limited thereto. The converter 250 maybypass the input voltage Vin, and the voltage MOD 231 a may generate thevoltage modulation signal from the input voltage Vin according to thecontrol signal received from the controller 220. For example, thevoltage MOD 231 a may generate a voltage modulation signal, e.g., aplurality of voltage pulses, as the host request REQ, wherein thevoltage modulation signal toggles between a high voltage VH and a lowvoltage VL. The host request REQ may be provided to the first connectionterminal T1 of the first mobile device 100 b through the power line 300.

The voltage DEMOD 132 of the first mobile device 100 b may generate avoltage demodulation signal from the host request REQ and provide thevoltage demodulation signal to the controller 120. The controller 120may generate a control signal in response to the host request REQ andprovide the control signal to the current MOD 131. The current MOD 131may generate a current modulation signal according to the control signaland provide the current modulation signal to the current source 133. Thecurrent source 133 may generate, as the client response RES, a pluralityof current pulses toggling between a high current IH and a low currentIL according to the current modulation signal. The client response RESmay be provided to the second connection terminal T2 of the secondmobile device 200 b through the power line 300.

After receiving the client response RES, the controller 220 of thesecond mobile device 200 b may change the PLC mode from the low-speedPLC mode to the high-speed PLC mode and thus set the impedance Z2 of thevariable impedance unit 210 a to be relatively high. Similarly, aftertransmitting the client response RES, the controller 120 of the firstmobile device 100 b may change the PLC mode from the low-speed PLC modeto the high-speed PLC mode and thus set the impedance Z1 of the variableimpedance unit 110 a to be relatively high.

A time period from the time point t2 to a time point t7 may correspondto a data transfer phase 62. At this time, the first and second mobiledevices 100 b and 200 b may operate in the high-speed PLC mode. Theimpedances Z1 and Z2 of the variable impedance units 110 a and 210 arespectively included in the first and second mobile devices 100 b and200 b may be relatively high. In some example embodiments, the impedanceZ1 of the variable impedance unit 110 a may be equal or similar to theimpedance Z2 of the variable impedance unit 210 a in the data transferphase 62. However, some example embodiments are not limited thereto. Insome example embodiments, the impedance Z1 of the variable impedanceunit 110 a may be different from the impedance Z2 of the variableimpedance unit 210 a in the data transfer phase 62.

In the data transfer phase 62, the converter 250 of the second mobiledevice 200 b may be deactivated, and the second mobile device 200 b mayoperate using the battery voltage VBAT2 of the second battery 240 a. Forexample, the converter 250 may operate in a bypass mode that bypassesthe battery voltage VBAT2 of the second battery 240 a. In the datatransfer phase 62, the charger 150 of the first mobile device 100 b maybe deactivated, and the first mobile device 100 b may operate using thebattery voltage VBAT1 of the first battery 140 a. As described above,because the charger 150 of the first mobile device 100 b is deactivated,an operation of charging the first battery 140 a by transmitting powerfrom the second mobile device 200 b to the first mobile device 100 b maybe interrupted or substantially interrupted, and only data may betransmitted through PLC. However, some example embodiments are notlimited thereto. In some example embodiments, in the data transfer phase62, the charger 150 of the first mobile device 100 b may be activated,and both power and data may be transmitted through PLC.

In a time period from a time point t3 to a time point t4, the currentsource 233 of the second mobile device 200 b may be activated and thecurrent source 133 of the first mobile device 100 b may be deactivated.In detail, the current MOD 232 a of the second mobile device 200 b maygenerate a current modulation signal, and the current source 233 maygenerate a current pulse according to the current modulation signal andprovide the current pulse to the power line 300 through the secondconnection terminal T2. At this time, the voltage DEMOD 132 of the firstmobile device 100 b may generate a voltage demodulation signal from theline voltage V_(PL) of the first connection terminal T1 connected to thepower line 300.

In a time period from a time point t5 to a time point t6, the currentsource 133 of the first mobile device 100 b may be activated and thecurrent source 233 of the second mobile device 200 b may be deactivated.In detail, the current MOD 131 of the first mobile device 100 b maygenerate a current modulation signal, and the current source 133 maygenerate a current pulse according to the current modulation signal andprovide the current pulse to the power line 300 through the firstconnection terminal T1. At this time, the voltage DEMOD 232 b of thesecond mobile device 200 b may generate a voltage demodulation signalfrom the line voltage V_(PL) of the second connection terminal T2connected to the power line 300.

A time period following the time point t7 may correspond to a powertransfer phase 63. At this time, the first mobile device 100 b and thesecond mobile device 200 b may operate in the low-speed PLC mode. In thepower transfer phase 63, the converter 250 and the current MOD 231 a ofthe second mobile device 200 b may be activated, and the line voltageV_(PL) may maintain the high voltage VH. At a time point t8, the charger150 of the first mobile device 100 b may be activated, and the linecurrent I_(PL) may maintain the high current IH. Accordingly, the secondmobile device 200 b may transmit power to the first mobile device 100 bthrough PLC, and the charger 150 of the first mobile device 100 b maycharge the first battery 140 a.

FIG. 7 is a timing diagram of another example of PLC data exchangebetween the first mobile device MD1 and the second mobile device MD2,according to some example embodiments.

Referring to FIG. 7, a first graph 710 represents a line voltage overtime and may correspond to, for example, the line voltage V_(PL) of thefirst or second connection terminal T1 or T2 connected to the power line300 in FIG. 5. A second graph 720 represents a line current over timeand may correspond to, for example, the line current I_(PL) flowing inthe power line 300 in FIG. 5. For example, the first and second mobiledevices MD1 and MD2 may respectively correspond to the first and secondmobile devices 100 b and 200 b in FIG. 5. Hereinafter, descriptions willbe made with reference to FIGS. 5 and 7.

PLC data exchange according to some example embodiments corresponds to amodification of the PLC data exchange of FIG. 6 and is different fromthe PLC data exchange of FIG. 6 in a data transfer phase 72.Hereinafter, descriptions will be focused on the data transfer phase 72,and the descriptions given with reference to FIG. 6 may also be applied.The time period from the time point t1 to the time point t2 maycorrespond to a host/client define phase 71. The operations of the firstand second mobile devices 100 b and 200 b in the host/client definephase 71 may be the same as or substantially similar to those in thehost/client define phase 61 in FIG. 6.

The time period from the time point t2 to the time point t7 maycorrespond to the data transfer phase 72. At this time, the first andsecond mobile devices 100 b and 200 b may operate in the high-speed PLCmode. The impedances Z1 and Z2 of the variable impedance units 110 a and210 a respectively included in the first and second mobile devices 100 band 200 b may be relatively high.

Unlike FIG. 6, in the data transfer phase 72, the converter 250 of thesecond mobile device 200 b may be activated, and the second mobiledevice 200 b may maintain the high voltage VH even after the time pointt2. In the data transfer phase 72, the charger 150 of the first mobiledevice 100 b may be deactivated, and the first mobile device 100 b mayoperate using the battery voltage VBAT1 of the first battery 140 a. Asdescribed above, because the charger 150 of the first mobile device 100b is deactivated, an operation of charging the first battery 140 a bytransmitting power from the second mobile device 200 b to the firstmobile device 100 b may be interrupted or substantially interrupted, andonly data may be transmitted through PLC.

FIG. 8 illustrates a mobile system 10 c according to some exampleembodiments.

Referring to FIG. 8, the mobile system 10 c may include a first mobiledevice 100 c and a second mobile device 200 c. The first and secondmobile devices 100 c and 200 c may correspond to examples of the firstand second mobile devices 100 and 200 in FIG. 1.

The first mobile device 100 c may include the first connection terminalT1, the variable impedance unit 110 a, the controller 120, a PLC modem130 c, the first battery 140 a, and/or the charger 150. The PLC modem130 c may include a low-speed PLC modem 134 and a high-speed PLC modem135. The controller 120 may selectively activate the low-speed PLC modem134 and the high-speed PLC modem 135 according to the PLC mode. In someexample embodiments, the low-speed PLC modem 134 may include a voltagemodulator and a current demodulator; and the high-speed PLC modem 135may include a current modulator, a current source, and/or a voltagedemodulator. In some example embodiments, the low-speed PLC modem 134may include a current modulator, a current source, and/or a voltagedemodulator; and the high-speed PLC modem 135 may include a voltagemodulator and a current demodulator. However, some example embodimentsare not limited thereto. The configurations of the low-speed PLC modem134 and the high-speed PLC modem 135 may vary with some exampleembodiments.

The second mobile device 200 c may include the second connectionterminal T2, the variable impedance unit 210 a, the controller 220, aPLC modem 230 c, the second battery 240 a, and/or the converter 250. ThePLC modem 230 c may include the low-speed PLC modem 231 and a high-speedPLC modem 232′. The controller 220 may selectively activate thelow-speed PLC modem 231 and the high-speed PLC modem 232′ according tothe PLC mode. In some example embodiments, the low-speed PLC modem 231may include a voltage modulator and a current demodulator; and thehigh-speed PLC modem 232′ may include a voltage modulator and a voltagedemodulator. In some example embodiments, the low-speed PLC modem 231may include a current modulator, a current source, and/or a voltagedemodulator; and the high-speed PLC modem 232′ may include a voltagemodulator and a voltage demodulator. However, some example embodimentsare not limited thereto. The configurations of the low-speed PLC modem231 and the high-speed PLC modem 232′ may vary with some exampleembodiments.

FIG. 9 illustrates a mobile system 10 d according to some exampleembodiments.

Referring to FIG. 9, the mobile system 10 d may include a first mobiledevice 100 d and a second mobile device 200 d. The first and secondmobile devices 100 d and 200 d may correspond to examples of the firstand second mobile devices 100 c and 200 c in FIG. 8. The first andsecond mobile devices 100 d and 200 d may also correspond tomodifications of the first and second mobile devices 100 b and 200 b inFIG. 5. Hereinafter, descriptions will be focused on the differencesbetween the first and second mobile devices 100 d and 200 d and thefirst and second mobile devices 100 b and 200 b in FIG. 5.

When the first mobile device 100 d is connected to the second mobiledevice 200 d by the electrical contact between the first and secondconnection terminals T1 and T2, the line current I_(PL) may flow throughthe power line 300, and the respective voltages of the first and secondconnection terminals T1 and T2 may be the same as or similar to eachother at the line voltage V_(PL).

The first mobile device 100 d may include the first connection terminalT1, the variable impedance unit 110 a, the controller 120, a current MOD134 a, a voltage DEMOD 134 b, a voltage MOD 135 a, a current source 136,the first battery 140 a, and/or the charger 150. According to the PLCmode, the controller 120 may generate control signals for controllingthe current MOD 134 a, the voltage DEMOD 134 b, the voltage MOD 135 a,and/or the current source 136. At this time, the current MOD 134 a, thecurrent source 136, and/or the voltage DEMOD 134 b may be activated inthe low-speed PLC mode and may form the low-speed PLC modem 134 in FIG.8. The voltage MOD 135 a and the voltage DEMOD 134 b may be activated inthe high-speed PLC mode and may form the high-speed PLC modem 135 inFIG. 8.

In the low-speed PLC mode, the controller 120 may activate the currentMOD 134 a, the current source 136, and the voltage DEMOD 134 b anddeactivate the voltage MOD 135 a. In the low-speed PLC mode, the currentMOD 134 a may receive a control signal from the controller 120 andgenerate a current modulation signal according to the control signal.The current source 136 may generate a current pulse according to thecurrent modulation signal and provide the current pulse to the firstconnection terminal T1. The voltage DEMOD 134 b may generate a voltagedemodulation signal according to the line voltage V_(PL) of the firstconnection terminal T1 and provide the voltage demodulation signal tothe controller 120.

In the high-speed PLC mode, the controller 120 may activate the voltageMOD 135 a and the voltage DEMOD 134 b and deactivate the current MOD 134a and the current source 136. In the high-speed PLC mode, the voltageMOD 135 a may receive a control signal from the controller 120 andgenerate a voltage modulation signal according to the control signal.The voltage MOD 135 a may transmit the voltage modulation signal to thesecond mobile device 200 d through the first connection terminal T1. Thevoltage DEMOD 134 b may generate a voltage demodulation signal accordingto the line voltage V_(PL) of the first connection terminal T1 andprovide the voltage demodulation signal to the controller 120.

The second mobile device 200 d may include the second connectionterminal T2, the variable impedance unit 210 a, the controller 220, thevoltage MOD 231 a, the current DEMOD 231 b, a voltage MOD 232 a′, thevoltage DEMOD 232 b, the second battery 240 a, and/or the converter 250.As described above, while the second mobile device 200 b in FIG. 5includes the current MOD 232 a and the current source 233, the secondmobile device 200 d may include the voltage MOD 232 a′. The voltage MOD232 a′ and the voltage DEMOD 232 b may be activated in the high-speedPLC mode and may form the high-speed PLC modem 232′ in FIG. 8.

In the low-speed PLC mode, the controller 220 may activate the voltageMOD 231 a and the current DEMOD 231 b and deactivate the voltage MOD 232a′ and the voltage DEMOD 232 b. In the low-speed PLC mode, the voltageMOD 231 a may receive a control signal from the controller 220 andgenerate a voltage modulation signal according to the control signal.The voltage MOD 231 a may transmit the voltage modulation signal to thefirst mobile device 100 d through the variable impedance unit 210 a andthe second connection terminal T2. The current DEMOD 231 b may generatea current demodulation signal according to the line current I_(PL)received through the second connection terminal T2 and provide thecurrent demodulation signal to the controller 220.

In the high-speed PLC mode, the controller 220 may deactivate thevoltage MOD 231 a and the current DEMOD 231 b and activate the voltageMOD 232 a′ and the voltage DEMOD 232 b. In the high-speed PLC mode, thevoltage MOD 232 a′ may receive a control signal from the controller 220,generate a voltage modulation signal according to the control signal andprovide the voltage modulation signal to the second connection terminalT2. The voltage DEMOD 232 b may generate a voltage demodulation signalaccording to the line voltage V_(PL) of the second connection terminalT2 and provide the voltage demodulation signal to the controller 220.

FIG. 10 is a timing diagram of an example of PLC data exchange betweenthe first mobile device MD1 and the second mobile device MD2, accordingto some example embodiments.

Referring to FIG. 10, a first graph 1010 represents a line voltage overtime and may correspond to, for example, the line voltage V_(PL) of thefirst or second connection terminal T1 or T2 connected to the power line300 in FIG. 9. A second graph 1020 represents a line current over timeand may correspond to, for example, the line current I_(PL) flowing inthe power line 300 in FIG. 9. For example, the first and second mobiledevices MD1 and MD2 may respectively correspond to the first and secondmobile devices 100 d and 200 d in FIG. 9. Hereinafter, descriptions willbe made with reference to FIGS. 9 and 10.

The time period from the time point t1 to the time point t2 maycorrespond to a host/client define phase 101. At this time, the firstand second mobile devices 100 d and 200 d may operate in the low-speedPLC mode. The impedances Z1 and Z2 of the variable impedance units 110 aand 210 a respectively included in the first and second mobile devices100 d and 200 d may be relatively low. In some example embodiments, theimpedance Z1 of the variable impedance unit 110 a may be equal orsimilar to the impedance Z2 of the variable impedance unit 210 a in thehost/client define phase 101. However, some example embodiments are notlimited thereto. In some example embodiments, the impedance Z1 of thevariable impedance unit 110 a may be different from the impedance Z2 ofthe variable impedance unit 210 a in the host/client define phase 101.

In the host/client define phase 101, the second mobile device 200 d maytransmit the host request REQ to the first mobile device 100 d, and thefirst mobile device 100 d may transmit the client response RES to thesecond mobile device 200 d in response to the host request REQ.According to some example embodiments, the host request REQ and theclient response RES may be exchanged at least two times in thehost/client define phase 101.

In the host/client define phase 101, the converter 250 and the voltageMOD 231 a of the second mobile device 200 d may be activated, and thevoltage MOD 231 a may generate a voltage modulation signal from theconverted voltage Vc, which is received from the converter 250,according to a control signal received from the controller 220. However,some example embodiments are not limited thereto. The converter 250 maybypass the input voltage Vin, and the voltage MOD 231 a may generate thevoltage modulation signal from the input voltage Vin according to thecontrol signal received from the controller 220. For example, thevoltage MOD 231 a may generate a voltage modulation signal, e.g., aplurality of voltage pulses, as the host request REQ, wherein thevoltage modulation signal toggles between the high voltage VH and thelow voltage VL. The host request REQ may be provided to the firstconnection terminal T1 of the first mobile device 100 d through thepower line 300.

The voltage DEMOD 134 b of the first mobile device 100 d may generate avoltage demodulation signal from the host request REQ and provide thevoltage demodulation signal to the controller 120. The controller 120may generate a control signal in response to the host request REQ andprovide the control signal to the current MOD 134 a. The current MOD 134a may generate a current modulation signal according to the controlsignal and provide the current modulation signal to the current source136. The current source 136 may generate, as the client response RES, aplurality of current pulses toggling between the high current IH and thelow current IL according to the current modulation signal. The clientresponse RES may be provided to the second connection terminal T2 of thesecond mobile device 200 d through the power line 300.

After receiving the client response RES, the controller 220 of thesecond mobile device 200 d may change the PLC mode from the low-speedPLC mode to the high-speed PLC mode and thus set the impedance Z2 of thevariable impedance unit 210 a to be relatively high. Similarly, aftertransmitting the client response RES, the controller 120 of the firstmobile device 100 d may change the PLC mode from the low-speed PLC modeto the high-speed PLC mode and thus set the impedance Z1 of the variableimpedance unit 110 a to be relatively high.

The time period from the time point t2 to the time point t7 maycorrespond to a data transfer phase 102. At this time, the first andsecond mobile devices 100 d and 200 d may operate in the high-speed PLCmode. The impedances Z1 and Z2 of the variable impedance units 110 a and210 a respectively included in the first and second mobile devices 100 dand 200 d may be relatively high. In some example embodiments, theimpedance Z1 of the variable impedance unit 110 a may be equal orsimilar to the impedance Z2 of the variable impedance unit 210 a in thedata transfer phase 102. However, some example embodiments are notlimited thereto. In some example embodiments, the impedance Z1 of thevariable impedance unit 110 a may be different from the impedance Z2 ofthe variable impedance unit 210 a in the data transfer phase 102.

In the data transfer phase 102, the converter 250 of the second mobiledevice 200 d may be deactivated, and the second mobile device 200 d mayoperate using the battery voltage VBAT2 of the second battery 240 a. Forexample, the converter 250 may operate in a bypass mode that bypassesthe battery voltage VBAT2 of the second battery 240 a. In the datatransfer phase 102, the charger 150 of the first mobile device 100 d maybe deactivated, and the first mobile device 100 d may operate using thebattery voltage VBAT1 of the first battery 140 a. As described above,because the charger 150 of the first mobile device 100 d is deactivated,an operation of charging the first battery 140 a by transmitting powerfrom the second mobile device 200 d to the first mobile device 100 d maybe interrupted or substantially interrupted, and only data may betransmitted through PLC. However, some example embodiments are notlimited thereto. In some example embodiments, in the data transfer phase102, the charger 150 of the first mobile device 100 d may be activated,and both power and data may be transmitted through PLC.

In the time period from the time point t3 to the time point t4, thevoltage MOD 232 a′ of the second mobile device 200 d may be activatedand the voltage MOD 135 a of the first mobile device 100 d may bedeactivated. In detail, the voltage MOD 232 a′ of the second mobiledevice 200 d may generate a voltage modulation signal and provide thevoltage modulation signal to the power line 300 through the secondconnection terminal T2. For example, the voltage modulation signal mayinclude a plurality of voltage pulses toggling between an input/outputvoltage VIO and 0 V. At this time, the voltage DEMOD 134 b of the firstmobile device 100 d may generate a voltage demodulation signal from theline voltage V_(PL) of the first connection terminal T1 connected to thepower line 300.

In the time period from the time point t5 to the time point t6, thevoltage MOD 135 a of the first mobile device 100 d may be activated andthe voltage MOD 232 a′ of the second mobile device 200 d may bedeactivated. In detail, the voltage MOD 135 a of the first mobile device100 d may generate a voltage modulation signal and provide the voltagemodulation signal to the power line 300 through the first connectionterminal T1. For example, the voltage modulation signal may include aplurality of voltage pulses toggling between the input/output voltageVIO and 0 V. At this time, the voltage DEMOD 232 b of the second mobiledevice 200 d may generate a voltage demodulation signal from the linevoltage V_(PL) of the second connection terminal T2 connected to thepower line 300.

The time period following the time point t7 may correspond to a powertransfer phase 103. At this time, the first mobile device 100 d and thesecond mobile device 200 d may operate in the low-speed PLC mode. In thepower transfer phase 103, the converter 250 and the current MOD 231 a ofthe second mobile device 200 d may be activated, and the line voltageV_(PL) may maintain the high voltage VH. At the time point t8, thecharger 150 of the first mobile device 100 d may be activated, and theline current I_(PL) may maintain the high current IH. Accordingly, thesecond mobile device 200 d may transmit power to the first mobile device100 d through PLC, and the charger 150 of the first mobile device 100 dmay charge the first battery 140 a.

FIG. 11 illustrates a mobile system 10 e according to some exampleembodiments.

Referring to FIG. 11, the mobile system 10 e may include a first mobiledevice 100 e and a second mobile device 200 e. The first and secondmobile devices 100 e and 200 e may correspond to examples of the firstand second mobile devices 100 and 200 in FIG. 1. The descriptions givenabove with reference to FIGS. 1 through 10 may also be applied to FIG.11.

The first mobile device 100 e may include the first connection terminalT1, the variable impedance unit 110, the controller 120, the PLC modem130, the first battery 140, a PMIC 160, and/or a wireless communicationunit 170. The variable impedance unit 110, the controller 120, the PLCmodem 130, the first battery 140, the PMIC 160, and/or the wirelesscommunication unit 170 may be mounted on a PCB. The PMIC 160 may managethe power of the first battery 140. In some example embodiments, thecharger 150 in FIG. 3 may be implemented as a part of the PMIC 160. Insome example embodiments, the first mobile device 100 e may furtherinclude a charger or a charging IC.

The wireless communication unit 170 may wirelessly communicate with amain device 400. For example, the wireless communication unit 170 mayinclude a Bluetooth module and may receive data from the main device 400through Bluetooth communication. For example, the main device 400 mayinclude, but is not limited to, a smart phone, a tablet personalcomputer (PC), a PC, a smart television (TV), a cellular phone, apersonal digital assistant (PDA), a laptop, a media player, a microserver, a global positioning system (GPS) device, an e-book terminal, adigital broadcasting terminal, a navigation device, a kiosk, an MP3player, a digital camera, and/or other mobile or non-mobile computingdevices. In another example, the main device 400 may include wearabledevices, such as a watch, glasses, a hairband, and/or a ring, which havecommunication and data processing functions.

The second mobile device 200 e may include the second connectionterminal T2, the variable impedance unit 210, the controller 220, thePLC modem 230, the second battery 240, and/or a PMIC 260. The variableimpedance unit 210, the controller 220, the PLC modem 230, the secondbattery 240, and/or the PMIC 260 may be mounted on a PCB. The PMIC 260may manage the power of the second battery 240. In some exampleembodiments, the converter 250 in FIG. 3 may be implemented as a part ofthe PMIC 260. In some example embodiments, the second mobile device 200e may further include a converter. The second mobile device 200 e mayalso include the input voltage terminal Tin receiving the input voltageVin from the outside thereof.

The wireless communication unit 170 of the first mobile device 100 e mayreceive data from the main device 400 and transmit the data to thesecond mobile device 200 e using PLC. At this time, a host device may bethe first mobile device 100 e and a client device may be the secondmobile device 200 e. Hereinafter, the PLC mode between the first andsecond mobile devices 100 e and 200 e will be described with referenceto FIGS. 2 and 11.

In the power transfer phase 21, the second mobile device 200 e maytransmit power to the first mobile device 100 e. At this time, the PLCmode between the first and second mobile devices 100 e and 200 e may bedetermined to be the low-speed PLC mode. In the host/client define phase22, a host transmitting data and a client receiving the data may bedetermined between the first and second mobile devices 100 e and 200 e.At this time, the PLC mode between the first and second mobile devices100 e and 200 e may be still determined to be the low-speed PLC mode.For example, the first mobile device 100 e may be determined to be thehost and the second mobile device 200 e may be determined to be theclient.

In the data transfer phase 23, the host may transmit data to the client.At this time, the PLC mode between the first and second mobile devices100 e and 200 e may be determined to be the high-speed PLC mode. Forexample, the first mobile device 100 e may transmit data to the secondmobile device 200 e. In the data transfer phase 23, the main function ofthe power line 300 may be changed from power transfer to data transfer.In some example embodiments, only data may be transmitted through thepower line 300 in the data transfer phase 23. However, some exampleembodiments are not limited thereto. Power and data may be transmittedthrough the power line 300 in the data transfer phase 23.

Based on completion of the data transfer, a power transfer phase 24begins anew, and the PLC mode between the first and second mobiledevices 100 e and 200 e may be determined to be the low-speed PLC mode.The main function of the power line 300 may be changed from datatransfer to power transfer in the power transfer phase 24. In someexample embodiments, only power may be transmitted through the powerline 300 in the power transfer phase 24. However, some exampleembodiments are not limited thereto. Data and power may be transmittedthrough the power line 300 in the power transfer phase 24.

FIG. 12 is a flowchart of the operations among the first mobile device100 e, the second mobile device 200 e, and the main device 400,according to some example embodiments.

Referring to FIG. 12, the main device 400 may transmit data to the firstmobile device 100 e in operation S200. For example, the data maycorrespond to firmware. For example, the main device 400 may transmitthe data to the first mobile device 100 e through wireless communicationsuch as Bluetooth communication. However, some example embodiments arenot limited thereto. The first mobile device 100 e may further include aconnection terminal for data exchange with the main device 400 and mayreceive data from the main device 400 through electrical contact of theconnection terminal to the main device 400.

The first mobile device 100 e may generate a host request (e.g., REQ inFIG. 6) in operation S210. The first mobile device 100 e transmits thehost request to the second mobile device 200 e in operation S220. Thesecond mobile device 200 e may generate a client response (e.g., RES inFIG. 6) in response to the host request in operation S230. The secondmobile device 200 e may transmit the client response to the first mobiledevice 100 e in operation S240. For example, operations S210 throughS240 may correspond to the host/client define phase 22 in FIG. 2, andboth of the first and second mobile devices 100 e and 200 e may operatein the low-speed PLC mode. At this time, the impedances Z1 and Z2 of thevariable impedance units 110 and 210 respectively included in the firstand second mobile devices 100 e and 200 e may be relatively low.According to some example embodiments, the operations S210 through S240may correspond to a detection that the first mobile device 100 e hasreceived firmware from the main device 400 (e.g., a firmware updateand/or firmware configured to repair a failure in an IC of the secondmobile device 200 e) that should be transferred to the second mobiledevice 200 e, and/or a request that the first mobile device 100 etransfer the firmware update to the second mobile device 200 e.

The second mobile device 200 e may determine the PLC mode to be thehigh-speed PLC mode in operation S250 (e.g., based on the clientresponse sent in operation S240). Accordingly, the impedance Z2 of thevariable impedance unit 210 of the second mobile device 200 e mayincrease, the high-speed PLC modem (e.g., 232 in FIG. 3) may beactivated, and the low-speed PLC modem (e.g., 231 in FIG. 3) may bedeactivated. The first mobile device 100 e may determine the PLC mode tobe the high-speed PLC mode in operation S255 (e.g., based on the clientresponse). Accordingly, the impedance Z1 of the variable impedance unit110 of the first mobile device 100 e may increase. Operations S250 andS255 may be performed substantially simultaneously or contemporaneously.

The first mobile device 100 e may transmit data to the second mobiledevice 200 e in operation S260. For example, the data may correspond tofirmware, and the first mobile device 100 e may transmit the firmware,which is downloaded from the main device 400, to the second mobiledevice 200 e. When a failure occurs in an IC after the second mobiledevice 200 e is launched, the second mobile device 200 e may repair thefailure in the IC using the firmware received from the first mobiledevice 100 e. For example, operations S250 through S260 may correspondto the data transfer phase 23 in FIG. 2. According to some exampleembodiments, the second mobile device 200 e may store, install and/orexecute the received firmware following operation S260. According tosome example embodiments, the second mobile device 200 e may repair thefailure of the IC using the received firmware following operation S260.

The second mobile device 200 e may determine the PLC mode to be thelow-speed PLC mode in operation S270 (e.g., based on completion of thedata transfer in operation S260). Accordingly, the impedance Z2 of thevariable impedance unit 210 of the second mobile device 200 e maydecrease, the low-speed PLC modem (e.g., 231 in FIG. 3) may beactivated, and the high-speed PLC modem (e.g., 232 in FIG. 3) may bedeactivated. The first mobile device 100 e may determine the PLC mode tobe the low-speed PLC mode in operation S275 (e.g., based on completionof the data transfer in operation S260). Accordingly, the impedance Z1of the variable impedance unit 110 of the first mobile device 100 e maydecrease. Operations S270 and S275 may be performed substantiallysimultaneously or contemporaneously. The second mobile device 200 e maytransmit power to the first mobile device 100 e in operation S280. Forexample, operations S270 through S280 may correspond to the powertransfer phase 24 in FIG. 2.

According to some example embodiments, operations described herein asbeing performed by the first mobile device 100, the second mobile device200, the variable impedance unit 110, the controller 120, the PLC modem130, the variable impedance unit 210, the controller 220, the PLC modem230, the first mobile device 100 a, the second mobile device 200 a, thevariable impedance unit 110 a, the charger 150, the variable impedanceunit 210 a, the PLC modem 230 a, the converter 250, the low-speed PLCmodem 231, the high-speed PLC modem 232, the first mobile device 100 b,the second mobile device 200 b, the PLC modem 130 a, the current MOD131, the voltage DEMOD 132, the voltage MOD 231 a, the current DEMOD 231b, the current MOD 232 a, the voltage DEMOD 232 b, the first mobiledevice 100 c, the second mobile device 200 c, the PLC modem 130 c, thelow-speed PLC modem 134, the high-speed PLC modem 135, the first mobiledevice 100 d, the second mobile device 200 d, the current MOD 134 a, thevoltage DEMOD 134 b, the voltage MOD 135 a, the voltage MOD 232 a′, thefirst mobile device 100 e, the second mobile device 200 e, the PMIC 160,the wireless communication unit 170 and/or the PMIC 260 may be performedby processing circuitry. The term ‘processing circuitry,’ as used in thepresent disclosure, may refer to, for example, hardware including logiccircuits; a hardware/software combination such as a processor executingsoftware; or a combination thereof. For example, the processingcircuitry more specifically may include, but is not limited to, acentral processing unit (CPU), an arithmetic logic unit (ALU), a digitalsignal processor, a microcomputer, a field programmable gate array(FPGA), a System-on-Chip (SoC), a programmable logic unit, amicroprocessor, application-specific integrated circuit (ASIC), etc.

It will be understood that when an element is referred to as being“connected” or “coupled” to another element, it can be directlyconnected or coupled to the other element or intervening elements may bepresent. As used herein the term “and/or” includes any and allcombinations of one or more of the associated listed items.

Some example embodiments may be described with reference to acts andsymbolic representations of operations (e.g., in the form of flowcharts, flow diagrams, data flow diagrams, structure diagrams, blockdiagrams, etc.) that may be implemented in conjunction with units and/ordevices discussed in more detail below. Although discussed in aparticular manner, a function or operation specified in a specific blockmay be performed differently from the flow specified in a flowchart,flow diagram, etc. For example, functions or operations illustrated asbeing performed serially in two consecutive blocks may actually beperformed concurrently, simultaneously, or in some cases be performed inreverse order.

The various operations of methods described above may be performed byany suitable device capable of performing the operations, such asprocessing circuitry. For example, the operations of methods describedabove may be performed by various hardware and/or software implementedin some form of hardware (e.g., processor, ASIC, etc.).

The software may comprise an ordered listing of executable instructionsfor implementing logical functions, and may be embodied in any“processor-readable medium” for use by or in connection with aninstruction execution system, apparatus, or device, such as a single ormultiple-core processor or processor-containing system.

The blocks or operations of a method or algorithm and functionsdescribed in connection with some example embodiments disclosed hereinmay be embodied directly in hardware, in a software module executed by aprocessor, or in a combination of the two. If implemented in software,the functions may be stored on or transmitted over as one or moreinstructions or code on a tangible, non-transitory computer-readablemedium. A software module may reside in Random Access Memory (RAM),flash memory, Read Only Memory (ROM), Electrically Programmable ROM(EPROM), Electrically Erasable Programmable ROM (EEPROM), registers,hard disk, a removable disk, a CD ROM, or any other form of storagemedium known in the art.

While the inventive concepts have been particularly shown and describedwith reference to some example embodiments thereof, it will beunderstood that various changes in form and details may be made thereinwithout departing from the spirit and scope of the following claims.

What is claimed is:
 1. A first mobile device comprising: a connection terminal configured to electrically connect to a second mobile device; a variable impedance device connected to the connection terminal, the variable impedance device configured to vary an impedance; processing circuitry configured to change a power line communication (PLC) mode between the first mobile device and the second mobile device from a low-speed PLC mode to a high-speed PLC mode in response to receiving a message from the second mobile device, and control the impedance of the variable impedance device according to the PLC mode; and a PLC modem configured to receive power from the second mobile device or communicate data with the second mobile device based on the PLC mode, wherein the message is a host request, and the processing circuitry is further configured to send a client response to the second mobile device in response to receiving the host request from the second mobile device, and change the PLC mode between the first mobile device and the second mobile device from the low-speed PLC mode to the high-speed PLC mode in response to sending the client response.
 2. The first mobile device of claim 1, wherein the PLC modem is configured to receive the power from the second mobile device in the low-speed PLC mode; and the impedance of the variable impedance device corresponds to a first impedance in the low-speed PLC mode.
 3. The first mobile device of claim 2, wherein the PLC modem is configured to communicate the data with the second mobile device in the high-speed PLC mode; and the impedance of the variable impedance device corresponds to a second impedance in the high-speed PLC mode, the second impedance being higher than the first impedance.
 4. The first mobile device of claim 1, wherein the processing circuitry is configured to change the PLC mode from the high-speed PLC mode to the low-speed PLC mode based on completion of a data reception from the second mobile device.
 5. The first mobile device of claim 1, wherein the processing circuitry is configured to generate a control signal for controlling the PLC modem according to the PLC mode; and the PLC modem is configured to generate a current modulation signal according to the control signal, generate a current pulse according to the current modulation signal, provide the current pulse to the connection terminal, and generate a voltage demodulation signal according to a voltage of the connection terminal.
 6. The first mobile device of claim 1, wherein the processing circuitry is configured to generate a control signal for controlling the PLC modem according to the PLC mode; and the PLC modem is configured to operate in the high-speed PLC mode including generating a voltage modulation signal according to the control signal, providing the voltage modulation signal to the connection terminal, and generating a voltage demodulation signal according to a voltage of the connection terminal.
 7. The first mobile device of claim 1, wherein the processing circuitry is configured to generate a control signal for controlling the PLC modem according to the PLC mode; and the PLC modem is configured to operate in the low-speed PLC mode including generating a current modulation signal according to the control signal, generating a current pulse according to the current modulation signal, providing the current pulse to the connection terminal, and generating a voltage demodulation signal according to a voltage of the connection terminal.
 8. The first mobile device of claim 1, wherein the processing circuitry is configured to receive the data from a main device through wireless communication, and wherein the processing circuitry is configured to: determine the PLC mode to be the high-speed PLC mode; provide the data to the second mobile device in the high-speed PLC mode; and change the PLC mode from the high-speed PLC mode to the low-speed PLC mode based on completion of transmission of the data to the second mobile device.
 9. The first mobile device of claim 1, further comprising: a battery; and a power management integrated circuit (PMIC) configured to manage power of the battery, wherein the processing circuitry is configured to charge the battery with the power received from the second mobile device.
 10. The first mobile device of claim 1, wherein the first mobile device includes a wireless earbud; and the second mobile device includes a wireless charger.
 11. A second mobile device comprising: a connection terminal configured to electrically connect to a first mobile device; a variable impedance device connected to the connection terminal, the variable impedance device configured to vary an impedance; processing circuitry configured to change a power line communication (PLC) mode from a low-speed PLC mode to a high-speed PLC mode in response to receiving a message from the first mobile device, control the impedance of the variable impedance device according to the PLC mode, receive an input voltage from an external source, and generate a converted voltage from the input voltage; and a PLC modem configured to transmit power to the first mobile device or communicate data with the first mobile device based on the PLC mode, the power being based on the converted voltage, wherein the message is a client response, and the processing circuitry is further configured to receive the message from the first mobile device in response to sending a host request to the first mobile device, and change the PLC mode between the first mobile device and the second mobile device from the low-speed PLC mode to the high-speed PLC mode in response to receiving the message.
 12. The second mobile device of claim 11, wherein the PLC modem is configured to transmit the power to the first mobile device in the low-speed PLC mode; and the impedance of the variable impedance device corresponds to a first impedance in the low-speed PLC mode.
 13. The second mobile device of claim 12, wherein the PLC modem is configured to communicate the data with the first mobile device in the high-speed PLC mode; and the impedance of the variable impedance device corresponds to a second impedance in the high-speed PLC mode, the second impedance being higher than the first impedance.
 14. The second mobile device of claim 11, wherein the processing circuitry is configured to change the PLC mode from the high-speed PLC mode to the low-speed PLC mode based on completion of a data reception from the first mobile device.
 15. The second mobile device of claim 11, wherein the processing circuitry is configured to generate a control signal for controlling the PLC modem according to the PLC mode; and the PLC modem is configured to operate in the high-speed PLC mode including generating a current modulation signal according to the control signal, generating a current pulse according to the current modulation signal, providing the current pulse to the connection terminal, and generating a voltage demodulation signal according to a voltage of the connection terminal.
 16. The second mobile device of claim 12, wherein the processing circuitry is configured to generate a control signal for controlling the PLC modem according to the PLC mode; and the PLC modem is configured to operate in the high-speed PLC mode including generating a voltage modulation signal according to the control signal, providing the voltage modulation signal to the connection terminal, and generating a voltage demodulation signal according to a voltage of the connection terminal.
 17. The second mobile device of claim 11, wherein the processing circuitry is configured to generate a control signal for controlling the PLC modem according to the PLC mode; and the PLC modem is configured to operate in the low-speed PLC mode including generating a voltage modulation signal according to the control signal, providing the voltage modulation signal to the connection terminal, and generating a current demodulation signal according to a current received from the connection terminal.
 18. The second mobile device of claim 11, further comprising: a battery; and a power management integrated circuit (PMIC) configured to manage power of the battery, wherein the processing circuitry is configured to charge the battery based on the input voltage.
 19. The second mobile device of claim 11, wherein the processing circuitry is further configured to: determine the PLC mode to be the high-speed PLC mode; receive the data from the first mobile device in the high-speed PLC mode; and change the PLC mode from the high-speed PLC mode to the low-speed PLC mode based on completion of reception of the data from the first mobile device.
 20. The second mobile device of claim 11, wherein the first mobile device includes a wireless earbud; and the second mobile device includes a wireless charger. 